Increasing demand for communication over long distances, especially, for example, between continents will require infrastructure, such as subsea cables and connectors linking subsea cables and modules, e.g. subsea modules, such as transformers, pumps etc., that are located and operated reliably subsea. For example, in the oil and gas industry there is an increasing requirement for high performance subsea optical connectors.
Fibre optics are known for use in subsea connectors. Such an optical fibre is capable of carrying large volumes of data reliably and with minimal interference (such as from electromagnetic sources that would potentially effect traditional electronic transmissions). Due to the size and fragile nature of the contacting faces of the fibre optic ferrules, they must be protected from harsh conditions. They are extremely susceptible to damage from particles being trapped between the mating faces.
To isolate the internal parts and the optical contacts of the connector parts of such a connector from salt water and debris, as well as to support the mating of the female part with a male part of the connector, chambers of the connector parts are filled with an lubricant or compensation medium (oil, silicone gel etc.). With electrical connectors, the lubricant may also provide electrical insulation, although this is not a particular requirement for fibre optic connectors. During the mate, or due to thermal variances, a part of the lubricant will be displaced e.g. pushed into a volume compensator. For example, current compensation systems use elastomeric diaphragms as a barrier and as a means of pressure and thermal compensation between seawater and the connector. The pressure stabilising or compensating medium acts in conjunction with the elastomeric materials. To provide volume compensation during the mating or de-mating of the connector unit, a volume of the diaphragm may be changed by deforming the diaphragm or the compensating medium may be displaced from one connector part to the other connector part taking a route via a rigid walled chamber in a male pin connecting the compensating volumes of the connector parts.
Moreover, in conventional connectors a connecting structure comprising the optical fibre is, for example, positioned in a protecting sleeve during the mate and is only exposed in a clean environment shortly before the initial contacting of the corresponding fibre. To shorten the overall length of the connector and to provide a connector with e.g. several connecting structures and fibres, it is, for example, known to arrange the connecting axis off-centre and transversally from the centre axis of the connector.
Diaphragms used in these arrangements are, for example, arranged around the initials of the respective connector part. Hence, to provide sufficient flexible volumes the compensating volumes or the related structures such as diameter of the diaphragms or dimensions of the chamber in the male pin (such as for example, length, height, diameter etc.) had to be rather large. This results in a large and bulky connector. Furthermore, by compensating the volume by displacing the compensation medium from one connector part to the other connector part there is the risk of losing compensation medium in one connector part by uncompleted or disrupted displacement. Thus, a disturbed mating or un-mating sequence may occur, which may cause the total failure of the connector.